<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <title></title>
        <meta name="description" content="">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <link rel="stylesheet" href="">
    </head>
    <body>
        <script>
            let map1 = new Map([['name',  '张三'], ['age', 20]]);
            console.log(map1, 'map1');
            let map2 = new Map();
            map2.set('name', '李四');
            console.log(map2, 'map2');
            map2.set('age', 24);
            console.log(map2, 'map2');
            const age = map2.get('age');
            console.log(age, 'age');
            const isOr = map2.has('name');
            console.log(isOr, 'isOr');
            console.log(map2.size, 'map2.size');
            map1.delete('age');
            console.log(map1, 'map1');
            let map3 = new Map([['province', '湖南'], ['city', '长沙']]);
            map3.clear();
            console.log(map3, 'map3');
            let map4 = new Map([
                ['1111', 20],
                ['2222', 30],
                ['3333', 40],
                ['4444', 50],
                ['5555', 60],
                ['6666', 70],
            ]);
            const keys = map4.keys('4444');
            console.log(keys, 'keys');
        </script>
    </body>
</html>